Lentil, Kale and Sweet Potato Soup

1 medium onion, diced
1 large or 2 small carrots, diced
1 stalk celery, diced
1 1/2 cups brown lentils
4 cups vegetable broth
4 cups water
15-oz can petite-diced fire roasted tomatoes
1 large sweet potato, peeled and cubed (I used a white-fleshed variety)
handful of flat-leaf parsley, chopped
1 bay leaf
1/2 teaspoon fresh thyme (or dried)
1/2 teaspoon dried basil
Freshly ground black pepper to taste
6 cups chopped curly kale (stems removed)

Heat a large Dutch oven over medium-high heat (do not use a nonstick pan!). Add the onion, carrot and celery and cook, stirring, for 5-7 minutes, until vegetables soften and start to brown. Add the rest of the ingredients except kale. Bring to a boil, reduce the heat and simmer, partially covered, for 35-40 minutes, until sweet potatoes and lentils are tender. If the soup is too thick, add a little more broth or water. Season with salt to taste (if you used a salted broth, it should not need any more.) Add kale and cook another 5 minutes. Remove bay leaf and serve.

Serves 4